Waste-to-wealth for valorization of food waste to hydrogen and methane towards creating a sustainable ideal source of bioenergy

This review provides the insights for the conversion of food waste (FW) to electricity and heat energy and also to use FW as a source of bioenergy. The evaluations of bioenergy from FW conversion to commercially fulfil the energy demands of various nations were elucidated. Five countries attained the highest heating values from annual FW were: Canada - 4915 MJ/capita, The Netherlands - 3367 MJ/capita, the United Kingdom - 1497 MJ/capita, Japan - 1608 MJ/capita, and Sweden - 1278 MJ/capita. It is also shown that some countries could derive electricity from annual FW production and contribute a high percentage of total national electricity generation, such as The Netherlands - 2.9% (164.4 kW h/capita), Canada - 1.35% (240 kW h/capita), Japan - 0.92% (78.5 kW h/capita), the United Kingdom-1.31% (73.1 kW h/capita), and Ireland-1.23% (68 kW h/capita). Moreover, an analysis of Strengths-Weaknesses-Opportunities-Threats (SWOT) was used to assess three forms of FW bio-treatment processes including composting, anaerobic digestion, fermentation for bio-hythane gas, and thereby illustrating future directions in the development of fermenting FW to hydrogen and methane. The SWOT analysis indicates that the fermentative hydrogen and methane production was a promising option for commercializing FW into bioenergy. However, there is also a need to implement specific prevailing policies and regulations to stimulate this environment-friendly form of bioenergy production technology. Based on the above considerations, a conceptual model to develop the FW fermentation of bioenergy production was suggested.